Comparison between pre- and posttreatment clinical and renal biopsies in children receiving low dose ciclosporine-A for 2 years for steroid-dependentnephrotic syndrome

Background: The dose of ciclosporine-A (CSA) for long-term treatment of nep hrotic syndrome remains unclear due to the chronic nephrotoxicity of CSA. P atients and methods: We examined 14 children with steroid-dependent nephrot ic syndrome (SDNS) who showed signs of steroid toxicity and did not respond to cyclophosphamide. CSA was started at a dose between 2.0 and 3.3 mg/kg/d ay and the CSA dosage was decreased to between 1.6 and 3.1 mg/kg/day 4 mont hs after the initiation of CSA therapy to maintain 40 to 70 ng/ml in the wh ole blood trough level. Results: Renal histology before CSA therapy showed minimal changes in all patients. It was possible to discontinue corticoster oid therapy within 3 to 4 months in all patients. The SD score for height s ignificantly improved during CSA therapy. The incidence of CSA side-effects in our patients was lower than previously reported. Post-therapy biopsies after 24 months of CSA treatment showed mild tubular atrophy accompanying s tripped interstitial fibrosis in only 1 patient (7%), and positive findings of global sclerosed glomeruli in 2 patients. Conclusion Longterm CSA thera py in low doses was effective for patients with SDNS and demonstrated a low incidence of CSA side-effects including nephrotoxicity.